5.8
Acute poisoning
Recognise the commoner inhalants and ingestants responsible for accidental and
deliberate poisoning
Sign
Hypoventilation
Hyperventilation
Bradycardia
Tacharrythmia
Pinpoint pupils
Dilated pupils
Hypertension
Hyperthermia
Pyramidal signs,
ataxia, hypotonia,
hyperreflexia,
extensor plantars
Consider
Opiates, ethanol, benzodiazapines
Metabolic acidosis (aspirin, paracetamol), gastric aspiration, CO2
Opiates,
Tricyclics, anti-cholinergics, caffeine, theophilline, lithium, digoxin
Opiates, organophosphates
Methanol, anticholinergics, tricyclics, LSD
Ecstacy, amphetamines, cocaine
Ecstacy, amphetamines, anti-cholinergics
Drug
Opiates
Paracetamol / aspirin
Tricyclics
Ecstacy
Signs
Bradycardia, pinpoint pupils
Hyperventilatation
Tachyarrythmia, dilated pupils, tone + reflex changes, pyramidal signs
Hypertension, hyperthermia
Tricyclics or anti-cholinergics
Participate in the management of the commoner poisonings
Always record:
 GCS
 Respiratory rate
 Heart rate
 Pupil dilatation (even if normal)
 Blood pressure
 Temperature
 Tone & reflexes
Investigations
 BM
 ABG
 U+E, LFT
 Urine screen
 ECG (characteristic in some poisonings)
 Salicylate
 Paracetamol level 4 hrs post ingestion, and
again 4 hrs later.
Salicylate and paracetamol levels are always ordered at some trusts in any OD
Always contact the local poisons unit – telephone number in BNF.
Priorities are
 Resuscitation – ABC + IV access
 Intubate if GCS <8 and non-responsive to naloxone (opiates) or flumazenil (benzodiazepines)
 Fluids if hypotensive
 Prevention of further absorption of the poison
 Activated charcoal (50g) may be given – most useful in the first hour. Reduces absorption.
 Activated charcoal (50g) may be given 2 hourly – reduces enterohepatic cycling. May be easier
to give via NG tube as it tastes foul…
 If it has been <1 hour since the poisoning then gastric lavage is useful – contraindicated for
corrosive substances or hydrocarbons. Reduces absorption.
 Specific management (see below)
For control of fits, benzodiazepines may be given – consider PR if IV access is difficult
Always contact the local poisons unit – telephone number in BNF.
Toxin
Opiate
Aspirin
Immediate action
Check and monitor breathing
Paracetamol
Gastric lavage if within 4 hours
Paracetamol levels at 4 hours*
Antidepressants
Activated charcoal
Benzodiazepines
Protect airway
 blockers
Digoxin
Lithium
Check K+ and ECG
Gastric lavage
CO2
ABG, ECG, 100% O2
Antidote
Naloxone (short half-life)
Alkaline diuresis, haemodialysis
N-acetylcysteine (NAC)*
Diazepam for convulsions
Cardiac monitoring
Flumazenil if severe
Atropine (3 mg), glucagons 7 mg IM,
consider pacing.
Digibind ® binding antibody
Diuresis, dialysis
Diazepam for fits, consider hyperbaric
oxygen if available.
*NAC has an unpleasant side effect profile and is not automatically indicated in all overdose.
Take paracetamol levels 4 hours post ingestion (or later if presentation is after 4 hours) and
measure serum level against time post OD on the graph in the BNF – this will tell you whether to
give or withhold NAC. As an F1 doctor, always seek a senior opinion.
The BNF table has 2 levels – the upper line is for the majority of patients – the lower level is for
those who already are receiving enzyme inducing drugs, malnourished (e.g. alcoholics) or for
some other patient groups (see BNF for details).
History taking:
If the patient is responsive and coherent then a history can be taken after ABC assessment. If this
is not the case then try to get a history from family, friends, ambulance crew or anyone else who
may be able to provide details.
 What did they take: all drugs including alcohol; how much?
 When did they take them?
 Why did they take them: assess suicidal ideation.
Get help from:
 TOXBASE: www.spib.axl.co.uk
 BNF: Section on poisoning emergencies at the front
 National poisons centre: Telephone number in BNF
 Seniors!
Make an assessment of the underlying social and psychiatric factors in deliberate selfharm and the likelihood of a repetition
In some trusts (including Walsgrave) a formal psychiatric assessment is required of any patient
who has deliberately taken an overdose – remember to check local trust policies. Such
assessment may be requested when the patient is stabilized.
Risk factors for self-harm
Demographic / epidemiology
 Previous Hx self-harm
 Younger
 Female > Male
 Low SES
 Divorced and younger single
 Teenage wives
Illness related
 Psychiatric illness less common, less
severe
 Personality disorder (especially
borderline)
 Alcohol dependence
 Poor physical health
Other
 Early parental loss
 Parental neglect or abuse
 Long term social problems: family,
employment, financial
Risk factors for suicide
Demographic / epidemiology
 Previous Hx Suicide or self-harm
 Older*
 Male > Female
 Single, separated, widowed
 Unemployed
Illness related
 Psychiatric illness common, severe
 Depressive illness
 Alcohol abuse
 Drug abuse
 Schizophrenia
 Personality disorder
 Chronic pain or epilepsy
Other
 Threats of suicide
 Proposed plan
 Preparatory acts (e.g. saving pills) or
‘putting affairs in order’
* It is important that attempted suicide should always be taken seriously in the elderly [1]. Attempts in the elderly are a much
stronger predictor of subsequent completed suicide compared with attempts in younger people, with a ratio of attempts to
completion estimated to be around 4:1 compared with between 8 and 200:1 for young people who attempt suicide [1].
Suicidal behaviour in the elderly is undertaken with greater intent (less often expressed) and with greater lethality than in
younger age groups. Significant factors include: bereavement, social isolation and loneliness with depressive illness as
the most important predictor[1]. [1] H Cattell. Suicide in the elderly. Advan. in Psychiatr. Treat. 2000; 6: 102-8.